This invention relates to thermoplastic polymers having pendant hydroxyl moieties and phenoxyether moieties and to articles prepared from such polymers.
Hydroxyphenoxyether polymers have good barrier to oxygen, having oxygen transmission rates (OTR) of less than 10 cm.sup.3 -mil/100 in.sup.2 -atm-day. These polymers are therefore useful in packaging oxygen-sensitive materials. See, for example. Reinking et al, J. Poly Sci., Vol. 7, pp. 2135-2144, pp. 2145-2152 and pp. 2153-2160 (1963) and Encyclopedia of Polymer Science and Technology, Vol. 10, pp. 111-122. However, these hydroxyphenoxyether polymers have only moderate heat resistance, typified by glass transition temperatures (T.sub.g) below about 115.degree. C. Attempts have been made to increase the heat resistance of tlhese hydroxyphenoxyether polymers. However, hydroxyphenoxyether polymers modified to exhibit increased heat resistance and exhibit T.sub.g above 115.degree. C. generally suffer diminished barrier performance with OTR as high as 75 cm.sup.3 -mil/100 in.sup.2 -atm-day.
In view of the limited barrier properties and heat resistance of polymers having pendant hydroxyl moieties and phenoxyether moieties, it would be highly desirable to provide a polymer possessing a combination of genuinely good barrier (i.e., oxygen transmission rate less than 10.0 cm.sup.3 -mil/100 in.sup.2 -atm-day) and high heat resistance (i.e., Tg above 120.degree. C.).